System and method for providing selective voice call continuity

Abstract

A method for selectively establishing a voice call continuity link between a mobile device and a voice call continuity application server includes the steps of receiving a request to establish a voice over IP call connection at the voice call continuity application server from the mobile device, the request including mobile device location information for the mobile device. The method determines at the voice call continuity application server whether the voice call continuity link is needed between the voice call continuity server and the mobile device responsive to the mobile device location information within the request and network location information stored within a database associated with the voice call continuity application server. The method establishes the voice call continuity link between the mobile device and the voice call continuity application responsive to a determination that the voice call continuity link is needed.

What is claimed is: 
     
       1. A method for selectively establishing a voice call continuity link between a mobile device and a voice call continuity application server, comprising:
 receiving a request to establish a voice over IP call connection at the voice call continuity application server from the mobile device, the request including mobile device location information for the mobile device; 
 determining at the voice call continuity server a position of the mobile device with respect to at least one network defined by network location information that can support the voice over IP call if the voice over IP call is dropped by an IP network responsive to the mobile device location information; 
 determining at the voice call continuity application server whether the voice call continuity link is needed between the voice call continuity server and the mobile device responsive to the determined position of the mobile device with respect to the at least one network; 
 establishing the voice call continuity link between the mobile device and the voice call continuity application responsive to a determination that the voice call continuity link is needed; and 
 establishing a voice over IP call connection without the voice call continuity link responsive to a determination that the voice call continuity link is not needed. 
 
     
     
       2. The method of  claim 1 , wherein the step of determining further comprises: extracting the mobile device location information from the request. 
     
     
       3. The method of  claim 2 , wherein the step of determining a position further comprises:
 accessing the database associated with the voice call continuity server; 
 determining if the mobile device is within an area where an eHRPD (evolved high rate packet data) network is not available; and 
 determining if the IP network supporting the mobile device overlaps with a 1xRTT (single carrier Radio Transmission Technology) network. 
 
     
     
       4. The method of  claim 3 , wherein the step of establishing the voice call continuity link between the mobile device and the voice call continuity application server occurs responsive to a determination that the mobile device is not within the area where the eHRPD network is available and the IP network supporting the mobile device only overlaps with a 1xRTT network. 
     
     
       5. The method of  claim 3  further including the step of establishing a voice over IP call connection without the voice call continuity link responsive to a determination that either the mobile device is within the area where the eHRPD network is available or the IP network supporting the mobile device does not overlap with a 1xRTT network. 
     
     
       6. The method of  claim 1  further including the step of generating the request at a SIP client within the mobile device. 
     
     
       7. The method of  claim 6 , wherein the step of generating the request further comprises the step of generating a SIP (Session Initiation Protocol) INVITE message having the mobile device location information within a PANI (P-Access-Network-Info) header of the SIP INVITE message as the request. 
     
     
       8. A method for selectively establishing a voice call continuity link between a mobile device and a voice call continuity application server, comprising:
 receiving a request to establish a voice over IP call connection at the voice call continuity application server from the mobile device, the request including mobile device location information for the mobile device; 
 extracting the mobile device location information from the request; 
 accessing network location information for at least one network that can support the voice over IP call if it is dropped by an IP network from a database associated with the voice call continuity application server; 
 determining a position of the mobile device with respect to the at least one network defined by the network location information that can support the voice over IP call if it is dropped by an IP network; 
 determining at the voice call continuity application server whether the voice call continuity link is needed between the voice call continuity server and the mobile device responsive to the determined position; 
 establishing the voice call continuity link between the mobile device and the voice call continuity application responsive to a determination that the voice call continuity link is needed; and 
 establishing a voice over IP call connection without the voice call continuity link responsive to a determination that the voice call continuity link is not needed. 
 
     
     
       9. The method of  claim 8 , wherein the step of determining a position further comprises:
 determining if the mobile device is within an area where an eHRPD network is not available; and 
 determining if the IP network supporting the mobile device overlaps with a 1xRTT network. 
 
     
     
       10. The method of  claim 9 , wherein the step of establishing the voice call continuity link between the mobile device and the voice call continuity application server occurs responsive to a determination that the mobile device is not within the area where the eHRPD network is available and the IP network supporting the mobile device only overlaps with a 1xRTT network. 
     
     
       11. The method of  claim 9 , wherein the step of establishing the voice over IP call connection without the voice call continuity link responsive to a determination that either the mobile device is within the area where the eHRPD network is available or the IP network supporting the mobile device does not overlap with a 1xRTT network. 
     
     
       12. The method of  claim 8  further including the step of generating the request at a SIP client within the mobile device. 
     
     
       13. The method of  claim 12 , wherein the step of generating the request further comprises the step of generating a SIP INVITE message having the mobile device location information within a PANI header of the SIP INVITE message as the request. 
     
     
       14. A system for selectively establishing a voice call continuity link, comprising:
 a voice call continuity application server for receiving a receiving a request to establish a voice over IP call connection at the voice call continuity application server from a mobile device, the request including mobile device location information for the mobile device; 
 a database associated with the voice call continuity application server for storing network location information for at least one network that can support the voice over IP call if it is dropped by an IP network from the database associated with the voice call continuity application server; 
 wherein the voice call continuity application server determines whether the voice call continuity link is needed between the voice call continuity server and the mobile device responsive to the mobile device location information within the request and the network location information stored within the database based upon a position of the mobile device with respect to at least one network defined by the network location information that can support the voice over IP call; and 
 further wherein the voice call continuity application server establishes the voice call continuity link between the mobile device and the voice call continuity application responsive to a determination that the voice call continuity link is needed. 
 
     
     
       15. The system of  claim 14  further including an IP network server for establishing a voice over IP call connection without the voice call continuity link responsive to a determination that the voice call continuity link is not needed. 
     
     
       16. The system of  claim 14 , wherein the voice call continuity application server further extracts the mobile device location information from the request and determines the position of the mobile device with respect to at least one network defined by the network location information that can support the voice over IP call if it is dropped by an IP network. 
     
     
       17. The system of  claim 14 , wherein the voice call continuity application server further accesses the database associated with the voice call continuity server and determines if the mobile device is within an area where an eHRPD network is not available and if the IP network supporting the mobile device overlaps with a 1xRTT network. 
     
     
       18. The system of  claim 17 , wherein the voice call continuity application server establishes the voice call continuity link between the mobile device and the voice call continuity application server responsive to a determination that the mobile device is not within the area where the eHRPD network is available and the IP network supporting the mobile device only overlaps with a 1xRTT network. 
     
     
       19. The system of  claim 17  further including an IP network server for establishing a voice over IP call connection without the voice call continuity link responsive to a determination that either the mobile device is within the area where the eHRPD network is available or the IP network supporting the mobile device does not overlap with a 1xRTT network. 
     
     
       20. The system of  claim 14  further including a SIP client within a mobile device for generating the request. 
     
     
       21. The system of  claim 20 , wherein the SIP client further generates the request as a SIP INVITE message having the mobile device location information within a PANI header of the SIP INVITE message. 
     
     
       22. A system for selectively establishing a voice call continuity link, comprising:
 a SIP client within a mobile device for generating a request for a VoIP call as a SIP INVITE message having mobile device location information within a PANI header of the SIP INVITE message; 
 a voice call continuity application server for receiving a receiving the request to establish a voice over IP call connection at the voice call continuity application server from a mobile device, the request including mobile device location information for the mobile device; 
 a database associated with the voice call continuity application server for storing network location information for at least one network that can support the voice over IP call if it is dropped by an IP network from the database associated with the voice call continuity application server; 
 wherein the voice call continuity application server extracts the mobile device location information from the request and determines a position of the mobile device with respect to at least one network defined by the network location information that can support the voice over IP call if it is dropped by an IP network; 
 wherein the voice call continuity application server determines whether the voice call continuity link is needed between the voice call continuity server and the mobile device responsive to the determined position of the mobile device with respect to the at least one network; and 
 further wherein the voice call continuity application server establishes the voice call continuity link between the mobile device and the voice call continuity application responsive to a determination that the voice call continuity link is needed. 
 
     
     
       23. The system of  claim 22  further including an IP network server for establishing a voice over IP call connection without the voice call continuity link responsive to a determination that the voice call continuity link is not needed. 
     
     
       24. The system of  claim 22 , wherein the voice call continuity application server further accesses the database associated with the voice call continuity server and determines if the mobile device is within an area where an eHRPD network is not available and if the IP network supporting the mobile device overlaps with a 1xRTT network. 
     
     
       25. The system of  claim 24 , wherein the voice call continuity application server establishes the voice call continuity link between the mobile device and the voice call continuity application server responsive to a determination that the mobile device is not within the area where the eHRPD network is available and the IP network supporting the mobile device only overlaps with a 1xRTT network. 
     
     
       26. The system of  claim 24  further including an IP network server for establishing a voice over IP call connection without the voice call continuity link responsive to a determination that either the mobile device is within the area where the eHRPD network is available or the IP network supporting the mobile device does not overlap with a 1xRTT network.